KZ1000A1 1977 CARBI PROBLEM ...HELP..HELP

[Gosling1]

Good to hear that you have now got the bike running - I am not sure what you mean though by 'bottom out' for the floats ?

anyway - stock pilot jets for the 26mm carbs is 17.5

Drilling these out to 30 ?? that is a huge change in the pilot circuit. The most I have ever done on the 77 z1000's with these carbs, is gone up in size to 20 pilots - that was enough, together with adjusting the air-mixture screw, for a good rich mixture at idle....

What sort of air-filters are you running, and what sort of exhaust ??

Stock specs for the VM26SS carbies fitted to 1977 Z1000A1 or A2 carbies are as follows:

Main jet - 107.5
Needle jet - 0-8
Jet needle - 5CN8-3 ( 3 is the clip position - ie 3 down from the top = middle position out of 5)
Pilot jet - 17.5
Pilot air-screw - 1 1/4 turns out +- 1/8 turn
Throttle-valve cutaway - 1.5

Its entirely possible that these carbs could be off a 1976 z900 - they also used 26mm carbs. But the jetting specs and overall performance of the carbs is not that much different....if you could post up a couple of decent pictures - from above, behind and underneath - that may help me identify them ?

[Carbiez1000]

Funny that the mechanic said the same thing..... "This is outside the box" (17.5 > 20 norm) ( 25>?)
The needle seat under the float ( FLOAT VALVE ASSY ) one set the little pin went all the way in.. and the other set the pin was left out about 1mm from going all the way in...

The jet needle we have not looked at yet and would probably of an impact on the way we look and approach this.....

I purchased a Sudco carbi kit for my carbies.... the difference in pilot adjuster screw was very different...the sudco had a straight taper and the original tappered in and just before the tip they stepped down and tappered to a point.......If that makes any difference.
Oh how to I upload pictures?

[Gosling1]

the little pin that is attached to the float valve - is the 'needle' part of the 'needle & seat' assembly. These should all be replaced with new ones if they have not already been done ? All the needles should sit right up in the seat, if any of them are sitting 'out' a bit, that suggests to me that there is a bit of crap up in the 'seat' part.....although if you fitted a new set from Sudco......did you get a set specifically for the 77 z1000 or a z900 ? The earlier z900 had 28mm carbs.....and some slight detail differences.

Set the jet-needle to the middle position for all the initial jetting tests.

The pilot air-screws should all look identical. They should all look like the Sudco ones, with a straight taper to a point, for the OEM 26mm 1977 carbs.....

I think this is starting to sound a lot more like you have a set of 26 mm carbs fitted, that were originally fitted to another model.....this is not a huge problem, but it means that all the inner bits have to be exactly the same, not a mix'n'match of parts...once you get all the pilot air-screws the same, that should sort out the idle problem......but any further advice from that will require all the details on the rest of the bike - airbox or airfilter mods, exhaust system etc - and the jetting specs are really only a basic guide anyway.

You can either attach pictures using the 'upload attachment' box where you make a post (it is not in the 'quick reply' box, you have to click the Post Reply box to get the upload option) and then you just find the picture you want in your computer, double-click on it, and click the 'attach this file' button - and bingo, the picture will be attached to your post. You can also use a Photobucket account, but the upload attachment is easier....

[oldman]

I hope carbiez1000 posts some pictures of his fine machine. It was basically a basket case he has transformed into a new 1977 Kaw. It's beautiful. It looks like it just came off the showroom floor.

[Carbiez1000]

The bike sat on a fence out in a padock for 15 years....The shame of some people....... The man at the back is a good freind of mine and he found it for me....It cost me one box of beer? The pictures were taken 3 years ago

[metaltriumph]

more! what does it look like now?

[Carbiez1000]

Having problems with downloading these files...8 months

[Carbiez1000]

I am not trying to give you a build up, Every time I go to upload it drops out

[Carbiez1000]

These are the only recent photos I had...But I will upload a recent pic when I can....
To a few hardcore collectors I would be slamed for not being original to form
- pipes
- colour
- seat
-bars etc
But..........The BONES are all their

[oldman]

What a beautiful machine. I'm very jealous. Glad your getting the carbies sorted. You should start your own shop. Keep us posted on how the carbie shit is coming. If in fact you have the wrong carbies it should be fairly easy to sort out but watch your spark plug colours as they will give you an indication of fuel mixture. If it's lean down low chances are it will be lean up higher as well. The main jets may have to be increased in size. Black insulators on the spark plugs=rich, white or pitted=lean and a nice Jim Beam lite brown perfect. This is very important on an air cooled bike as a lean mixture means high temperatures meaning burn't exhaust valves and numerous other engine top end problems. Pull them after a moderate ride, (not too long) and check the colour.

[Gosling1]

Lookin' good there matey

[mike-s]

Have to agree with the old man, that is a beautiful job that you've done with that bike, i am happy to see it and even a little bit jealous actually.

[metaltriumph]

Hey Carbiez - looks great although i dont envy you organising those wires...

where did you get the front mud guard>? i have the same on my z650 but it has some ripples on the front. I was planning on just cutting it short with a dremel cut-off disc but if i could find a neater way i would prefer it.

If in fact you have the wrong carbies it should be fairly easy to sort out but watch your spark plug colours as they will give you an indication of fuel mixture. If it's lean down low chances are it will be lean up higher as well. The main jets may have to be increased in size. Black insulators on the spark plugs=rich, white or pitted=lean and a nice Jim Beam lite brown perfect. This is very important on an air cooled bike as a lean mixture means high temperatures meaning burn't exhaust valves and numerous other engine top end problems. Pull them after a moderate ride, (not too long) and check the colour.

Hey oldman - are there any issues with these motors if they are running a bit rich? i know all my plugs on the z650 are blackened.

[Carbiez1000]

The guard I got from some bloke in Australia about a year ago.....He was a ebay dealer.....It was in good condition and probably did not require rechroming.....but it went on the pile........ Watch ebay motors and always check other items for sale by the same seller....there is plenty of good parts....... just keep your head down and A........up and you will find one, or even ask them....they are very helpful.

Well the bike is up and running.....I sized up the pilot jets, around about 30,,,,,Ya I know.......what the?????? We have 110 main jet, and it seems it runs like a cut snake.....So with smiles all round....we put the bike on the Dyno and it ran through all gears....under load....and what ever we put it through almost to the letter.......Very happy......The mechanic it still not convinced that they are the right fit out for this bike but.....its working and its a good start in the right direction....I will be now on the hunt for the right set.....But for now I just wont to get it registered and on the road?????

[oldman]

Hey oldman - are there any issues with these motors if they are running a bit rich? i know all my plugs on the z650 are blackened? Quote, metaltriumph.
A bit rich is ok. Too rich will make it run cooler but can also wash the oil away from the rings causing excessive ring, cylinder wall wear as well as low compression. It can also create a carbon buildup on the cylinder heads, valves and the head, causing hot spots and pre ignition, (ping). It would have to be pretty rich to do this however but black plugs must effect your performance? Are they fouling the plugs pretty often? If not you are probably ok. If you are having to clean them often because of fouling I would get it rejetted until you get it right. I did this by buying a way small set of main jets, (this was on a 1977 Honda 750F supersport), plus a machinests drill bit set. I fitted the drill bit through the jet that fit the tightest and went to the next size larger until I got it right. If you screw up all you have to do is fill the hole with soldier and re drill it. The metering jets, (my terminology is all fucked up) could also be out of adjustment if you have them. You will also have much better performance if your mixture is right. Where are you folks finding all these late 70's machines?
An afterthought, perhaps it's just at high RPM's or low That you are rich, to find out have a friend follow you and in, say third gear go from a low RPM to red line having him/her note at what speeds you are blowing black smoke, if it's always then it is your main jets if it is only high RPM it probably is your metering jets. Keep in mind slightly darkened plugs that are not fouling are ok, it's just escessive fuel that will mess you up, very black plugs that are fouling.